1. Field of the Invention
The present invention relates to a wristwatch type cellular phone. In particular, it is suitable as a wristwatch type cellular phone that has a equipment body section having clocking functions of a clock and a wrist band so as to enable the equipment body section to be placed on or pulled out of a wrist, and where the equipment body section incorporates an electronic circuit of the phone section that transacts dialing functions.
2. Description of the Related Art
Recently, cellular phones have become smaller and lighter, and a wristwatch type cellular phone has been also developed. The wristwatch type cellular phone has a portion equivalent to a clocking section of a wristwatch, and a portion equivalent to phone section necessary for cellular phone functions (communications section, operation section, transmitter section (microphone), and receiver section (speaker), etc.). Various devices have been made regarding this type of wristwatch type cellular phone in light of operationality for making a phone call, and user-friendliness of transmitting or receiving a phone call, etc. (for example, refer to patent documents 1-8: Patent document 1 (JP patent laid-open No. 5-276056), Patent document 2 (JP patent laid-open No. 6-232950), Patent document 3 (JP patent laid-open No. 9-55679), Patent document 4 (JP patent laid-open No. 11-177663), Patent document 5 (JP patent laid-open No. 2000-286939), Patent document 6 (JP patent laid-open No. 2001-28620), Patent document 7 (JP patent laid-open No. 2001-45122), and Patent document 8 (JP patent laid-open No. 2001-345907).
However, regarding a conventional wristwatch type cellular phone, the operation section relating to phone functions is allocated on the surface or backside of the clocking section body, or on the wrist band as a hardware switch. When considering operationality, the operation section cannot be made in a too small manner. Thus, this causes a problem where the clocking section body or wrist band in which the operation section is mounted becomes larger than a normal clock not having phone functions, and mounting become remarkably worse.
Additionally, the conventional wristwatch type cellular phone has a problem involving antenna installation. It is relatively easier for a normal cellular phone to preserve sufficient space that can incorporate a retractable antenna into the chassis thereof. However, regarding wristwatch type cellular phone, the clocking section body is remarkably smaller than the cellular phone. Therefore, it is difficult to preserve sufficient space that can incorporate a retractable antenna. When intending to forcedly mount a retractable antenna, the clocking section body must be made larger. Nonetheless, mounting becomes worse.
Additionally, the aforementioned patent document 1 includes that a wrist band made with antenna material having adequate elasticity is formed and a loop formed when the wrist band is placed on the wrist is used as an antenna. However, this method is based on a condition where users make a phone call by putting the wrist band on their wrists. This dialing method is not suitable because the distance between the transmitter section and receiver section becomes less, and making a phone call becomes difficult.
In order to avoid such difficulty when making a phone call, it is proposed that the transmitter section and receiver section be positioned at the edge of the wrist band (for example, refer to the aforementioned patent documents 4, 7, and 8). In such case, calls are executed in a condition that the wrist band is removed from the wrist. However, under such condition, the loop antenna cannot be formed, and receiver sensitivity worsens. In particular, many calls are executed while in transit, when receiver sensitivity worsens due to a change of surrounding conditions, calls are cut off.
Additionally, the conventional wristwatch type cellular phone diverts the battery incorporated in the backside of dial plate for the use of clock, etc. and operates the phone functions. Thus, the battery of such wristwatch type cellular phone becomes used up to a greater extent than that of a normal clock without phone functions. Normally, the battery for the clock is compact and has a low capacity, and the battery must be frequently exchanged. Moreover, such battery exchange is required to be preformed by using specialized tools. Thus, this causes a remarkably troublesome issue.